The present invention relates to a technique on an adapter for a memory card and a memory card. Particularly, the present invention is concerned with a technique applicable effectively to an adapter for a memory card still smaller than a small-sized memory card such as a reduced-size MMC, as well as the memory card.
Such memory cards as a multi-media card (there is a standard established by Multi-Media Card Association; hereinafter referred to as MMC) and an SD card (there is a standard established by SD Card Association) are one of storage devices which store information in a semiconductor memory chip disposed in the interior thereof. In the memory cards in question, an access of information is made directly and electrically to a non-volatile memory formed in the semiconductor memory chip and thus there is no control of a mechanical system, so that the memory cards in question have such excellent characteristics as the read time being high and the replacement of a storage medium being easy in comparison with other storage devices. Besides, since the outline is relatively small-sized and light-weight, the memory cards in question are used mainly as auxiliary storage devices in devices required to be portable such as portable personal computers, portable telephones and digital cameras.
An MMC is a small-sized and light-weight memory card having a weight of 1.5 g, outline dimensions of 32 mm×24 mm and a thickness of 1.4 mm. It is provided with a thin plate-like cap of a generally quadrangular shape in plan having a largely chamfered corner portion and is also provided with a memory body fitted in a recess formed in a parts-accommodating surface. The memory body includes a wiring substrate, a semiconductor chip mounted on a main surface of the wiring substrate, and a resin sealing member for sealing the semiconductor chip. The semiconductor chip is electrically connected through wiring lines formed on the wiring substrate to plural external terminals formed on a back surface of the wiring substrate. The plural external terminals are exposed to the exterior and are connected electrically to an electronic device in which the MMC is incorporated.
A reduced-size MMC (Reduced Size MMC, hereinafter referred to as RSMMC) is a memory card (weight 0.8 g, outline dimensions 18 mm×24 mm, thickness 1.4 mm) of a size about half the size of the above MMC. An external terminal structure of the RSMMC has compatibility with the MMC and can be used as an MMC by using an adapter for a memory card.
Further, the above SD card is a memory card having a weight of 3 g, outline dimensions of 32 mm×24 mm and a thickness of 2.1 mm. It is the same in shape as the MMC though different in weight and thickness. The SD card is provided with two thin plate-like cases of a quadrangular shape in plan having a largely chamfered corner portion and is also provided with a memory body sandwiched in between the two cases. Plural apertures are formed in a back surface of one case in the SD card, plural external terminals formed on a back surface of the memory body are exposed from the apertures, and the external terminals of the SD card and an electronic device in which the SD card is incorporated are electrically connected with each other through the apertures. The foregoing MMC is also employable in most of electronic devices insofar as the electronic devices are configured so as to permit the use of the SD card.
As to the adapter for a memory card, a related description is found, for example, in Japanese Unexamined Patent Publication No. 2004-348557 (Patent Literature 1), in which there is disclosed a configuration of an adapter for converting such a small-sized memory card as RSMMC into an ordinary MMC size.
Further, for example in Japanese Unexamined Patent Publication No. 2004-133516 (Patent Literature 2) there is disclosed a configuration wherein a sealing portion which covers an IC body is provided in the exterior of such a memory card as MMC and the IC body is held firmly while being sandwiched in between a memory card case and the sealing portion.
[Patent Literature 1]
Japanese Unexamined Patent Publication No. 2004-348557
[Patent Literature 2]
Japanese Unexamined Patent Publication No. 2004-133516